SIMPLE PRESENT EXERCISES

http://baladre.info/english/sedaviwebfront/presimpneg.htm

http://www.montsemorales.com/gramatica/PresSimpNeg1Spt.htm

http://www.englishexercises.org/makeagame/viewgame.asp?id=4599

http://www.english-room.com/negative_5.htm

http://www2.arnes.si/~oskplucija4/ces/psnegative.htm